Structure of the tree stratum of three swamp forest communities in southern Brazil under different soil conditions

Abstract

Restinga forests are commonly known to be plant communities rather poor in tree species. This study aimed to describe and explain the association between the floristic-structural similarities and the environmental conditions in three Swamp Restinga Forest communities in southern Brazil. In 13 plots of 100 m 2 each, we sampled all individual trees (circumference at breast height >12 cm and height ≥3 m). We collected soil samples in each plot for chemical and textural analyses. Phytosociological parameters were calculated and different structural variables were compared between areas. The density of individuals did not differ between areas; however, the maximum height and abundance of species differed between the site with Histosols and the other two sites with Gleysols. Further, a canonical correspondence analysis based on a matrix of vegetation and that of environmental characteristics explained 31.5% of the total variation. The high floristic and environmental heterogeneity indicate that swamp-forests can shelter many species with low frequency. Most species were generalists that were not exclusive to this type of forest. Overall, our study showed that swamp-forests within the same region can show considerable differences in composition and structure and can include species-rich communities, mostly due to the presence of species with a broader distribution in the Atlantic Rainforest domain on sites with less stressful environmental conditions and without waterlogged conditions.

What does a phytophysiognomic mosaic reveal about mosses and liverworts from the subtropical Atlantic Forest?

“…That tendency of swampy forests to have less species richness than well-drained soils in other forest types has been corroborated by other authors (Sztutman & Rodrigues 2002;Silva et al 2007;Martins et al 2013). The species richness of swampy forests tends to increase with increased proximity to Dense Ombrophilous forests and diminishing soil water saturation (Mancino et al 2015).…”